3. Being Indecisive

Compare these two openers: "Hey, we should grab a coffee some time" vs. "Hey, would you possibly want to grab coffee with me, or maybe dinner? We could even see a movie."

In the first, you're basically asking her on a date, albeit phrased in a way that makes it seem like a foregone conclusion. This is good, because it projects confidence, and it gives her only one thing to wonder: Do I or do I not want to date this guy?

The second question, on the other hand, not only puts her in the position of wondering whether or not she wants to go on a date with you, but forces her to consider the venue, too. This is bad: Now you're burdening her with irrelevant extras and, worse, making yourself look indecisive. Stick to one point. If she'd rather do dinner than coffee, she'll let you know.